The Evolution of the Universe
The Formation of Planetary Systems
The Origin of Life
The coevolution of life in Earth
Along this series of conferences it will be communicated to the assisting audience the knowledge acquired along the last years on the Evolution of the Universe, on the properties of the living systems, including their adaptability and the Darwinian evolution of the living systems, and on the habitability conditions of celestial objects. This description will be further completed by discussions around the experimental issues, the circumstances related to exploration associated with the adaptation of Life to extreme conditions, and to the search of in situ Life in the Solar System. Colloquial language will be used, although in occasions the discussion will build over mathematical formulas that will, nevertheless, be addressed with a plain and accesible language.
The evolution of the Universe will be described in large scale, from the Big Bang to the origin of the planetary systems. There will be a description of the Universe's "geography" and history, highlighting the regularities observed in the process, which have allowed us to establish a connection between the Universe's morphology and chronology. Special emphasis will be given to the basic principles that lie beneath this connection.
We will also talk about the formation of the planetary systems in general, and of our Solar System in particular, discussing the latest ideas around the creation of the two types of planets that exist in our planetary system: rocky and gas giants. The most important scenarios currently contemplated for the origin of life in our planet will be presented. Next, some of the most important episodes of co-evolution of life in our planet will be explained, finalizing with the discussion on the properties defining living systems that are currently contemplated.
The biology of extremophiles will also be included, paying special attention to the case of the Tinto river, and lastly we will describe the new types of instruments that, based on the current knowledge about Life and the habitability conditions, are being designed to explore the Solar System.
Finally, a few practical considerations of practical and aplicable nature around Life and habitability in our Blue Planet, the Earth, will be presented.
The adaptation of life to extreme conditions
Until rather recently we believed that life was essentially subtle and could only develop in environments similar to the ones that warm-blooded animals require (temperatures around 30ºC, pressure of one atmosphere, neutral pH, an ionic force similar to blood serum). The discovery of extremophiles, thus, organisms capable of developing in very atypical conditions (high temperature: 113ºC; low temperatures: -30ºC; low ionic force: absence of ions; high ionic force: 5M NaCl; low pH: 0; high pH: 12; high dosis of radiation; low pressure: 10-6 mb; elevated pressure: 1000 Mp; etc.,), has had very important implications in different fields of science in general, and of astrobiology in particular.
In this conference we will focus on the different habitats in which our protagonists, the extremophiles, develop with the aim of becoming familiarized with the levels of difficulty that the development of life has in each of them (the integrity of the membrane, the denaturalization of proteins and nucleic acids, osmotic pressure, speed of reaction, etc.), and this way, address the strategies applied by each of these organisms to counter the negative effects that an extreme condition or a sum of extreme conditions can pose.
Finally, we will focus on the study of microbial ecology in the Tinto river with aim of getting familiarized with the type of work that research on the ecology of extreme environments implies. The Tinto is an acid river (average pH 2.3) of more that 100 km of length that is originated by the metabolic activity of microorganisms capable of of growing by using metallic sulfurs as a source of energy, fundamentally pyrite, which exists in elevated concentrations in the Iberian Pyrite Belt. We will become familiarized with the mechanisms involved in the obtention of energy in strict chemolithoautotrophic microorganisms that develop in this environment, review the conventional techniques applied in microbial ecology and molecular ecology that are being used to explore this peculiar environment, analyze the data obtained to create a running model of the system, analyze some of the mineral byproducts produced by the microorganisms (goethite, jarosite , hematine, etc.), and their use for dating the age of the river. We will also see the mineralogical convergence between this environment produced by living beings in the Tinto river and the analogue case of Mars as described by the NASA MERs, and the perforation results in the Pyrite Belt (project MARTE). All of this, from an astrobiological perspective that will allow us to answer the fundamental questions about if life in our blue planet is just a matter of chance, or if it is the product from the evolution of the universe, implying that it may have also taken place in other planetary systems. Finally, the teachings from the acidophile organisms of Tinto river will be compared to other extreme models that have been generated so far.
Technology for the search of life in the Solar System
Within the Solar System, there are several bodies that could hold life in the present, of where life could have occurred in the past. Mars and Europa are two of them. Several missions have reached the first one and it is beginning to be known in detail, while the second one, much more far away, is completely unknown. How can we learn if life exists in these bodies? The only possible way we currently have is reaching them and exploring; either through orbiters, or through surface, airborne, or submarine vehicles; and of course, developing specific instruments. Thus, three development fields are associated with this task: the development of vehicles capable of reaching the bodies to be explored, of exploration vehicles, and of instruments.
The propulsion techniques currently being used in the space missions are a notable restriction for planetary exploration. Not only due to its high cost, but also to the extremely long duration of the voyages. Several alternatives are being evaluated, although are still far away of being able to replace what is currently applied. The exploration vehicles are one of the most critical elements in the search for life. Rovers are currently playing the main role, but the need to explore wider surfaces and complex orography makes it necessary to look for alternatives.
The instrumentation is probably the most key element in all missions, and their success depends on it very much. There are a number of techniques that are starting to be used in this field, some of them classic like infrared spectrometry and mass spectrometry. Others are totally new in the field of space like the Raman spectrometry; also biological techniques are starting to be incorporated such as the protein micro-matrixes or the capillary electrophoresis.
An important point to highlight is what in English is called Planetary Protection, referring to the need to avoid the contamination of the area to be explored by terrestrial components. This implies important restrictions to all the system (vehicle-instrumentation) applied in this exploration.